JP2013538910A - High functionality aromatic polyesters, polyol blends containing high functionality aromatic polyesters, and products obtained therefrom - Google Patents

Abstract

  The present invention discloses aromatic polyester polyols suitable for blending with other polyols, or other materials that are compatible with each other with polyester polyols, to provide polyurethane and polyisocyanurate products. Specifically, the present invention provides A) an aromatic component containing 80 mol% or more of terephthalic acid, and B) a nominal functionality of greater than 2 and less than or equal to 4, a molecular weight of 250 to 1000, and a polyoxypropylene content Comprising a reaction product of a polyether polyol in which at least 70% by weight of the polyol and C) a glycol other than B having a molecular weight of 60 to 250, wherein A, B and C are in the reaction product on a weight percent basis Polyester polyols are disclosed in which 20 to 60% by weight A), 15 to 70% by weight B) and 10 to 50% by weight C) are present.

Description

  The present invention generally relates to certain polyester polyols that are suitable for blending with other polyols or other materials that are compatible with each other to produce polyurethane and polyisocyanurate products.

  It is well known to use polyols in preparing polyurethanes by reacting polyols and polyisocyanates in the presence of a catalyst and optionally other components. Aromatic polyester polyols are one type of polyol that is widely used in the production of polyurethane foams and resins, and polyurethane-polyisocyanurate foams and resins.

  Aromatic polyester polyols are attractive when making polyurethane products. The reason for this is that aromatic polyester polyols tend to be inexpensive and can be adapted to a number of end uses where the product has good properties. One type of widely used aromatic polyester polyol is a polyol produced by esterifying phthalic acid or phthalic anhydride with an aliphatic polyhydric alcohol, such as diethylene glycol. This type of polyester polyol reacts with organic isocyanates to provide coatings, adhesives, sealants, and elastomers ("CASE materials") that can have excellent properties such as, for example, tensile strength, adhesion, and abrasion resistance. ) Can be generated. Such aromatic polyester polyols can also be used in formulations to produce rigid polyurethane foams or polyisocyanurate foams.

  One problem commonly encountered when using aromatic polyester polyols is that the functionality of aromatic polyester polyols is generally low, ie, the functionality is close to 2. Such low functionality generally has a negative impact on green compressive strength and compressive strength. High functionality glycols such as glycerin and pentaerythritol can be used to increase the functionality of the polyester polyol. However, such an increase in functionality usually comes at the expense of a large increase in viscosity.

  As demand for the use of blowing agents that do not reduce ozone, such as hydrocarbons, has increased, a further disadvantage of aromatic polyester polyols in formulations is that aromatic polyester polyols are generally more compatible with hydrocarbons. That is low. Efforts to improve the compatibility with hydrocarbons include polyester improvements such as the incorporation of fatty acids. Incorporation of fatty acids into the polyester results in a significant improvement in compatibility, but such improvement usually comes at the expense of polyester functionality or flame retardancy.

  Accordingly, there is a need for polyester polyols that are economical to produce, porous foams, and can be converted to other CASE materials with superior properties and are compatible with hydrocarbons. . It is further desirable to have an aromatic polyester polyol with low viscosity and good compatibility with hydrocarbons, which should be used in the production of polyurethane products that meet flame retardant standards based on aromatic content. Can do.

The present invention relates to a new class of aromatics having an average functionality of about 2.4 to 3, comprising a transesterification product of terephthalic acid and at least one polyether polyol having a nominal functionality of 3 to 4. It relates to a polyester polyol. In one aspect, the present invention provides at least A) an aromatic component comprising 80 mol% or more terephthalic acid,
B) at least one polyether polyol having a nominal functionality of greater than 2 and less than or equal to 4, a molecular weight of 250 to 1000, and a polyoxypropylene content of at least 70% by weight of the polyol;
C) comprising a reaction product with at least one glycol other than B having a molecular weight of 60 to 250, wherein A, B and C are 20 to 60% by weight A) in the reaction product, Polyester polyols in which 15 to 70% by weight of B) and 10 to 50% by weight of C) are present.

In another embodiment, the present invention provides:
A) an aromatic component containing 80 mol% or more of terephthalic acid,
B) at least one polyether polyol having a nominal functionality of greater than 2 and less than or equal to 4, a molecular weight of 250 to 1000, and a polyoxypropylene content of at least 70% by weight of the polyol;
C) consisting essentially of a reaction product with at least one glycol other than B having a molecular weight of 60 to 250, wherein A, B and C are 20 to 60% by weight based on the weight percent in the reaction product. A) Polyester polyol in which 15 to 70% by weight of B) and 10 to 50% by weight of C) are present. Specifically, the polyester is selected from the group consisting of (i) an equivalent weight of about 130-1000, (ii) containing about 8-60 carbon atoms, and (iii) carboxyl, hydroxyl and mixtures thereof. Made in the absence of about 0.1 to about 20 mole percent of at least one hydrophobic material characterized in that it contains at least one and no more than four groups per molecule to be formed.

  The invention also relates to a method for making such aromatic polyester polyols. In a further embodiment, the present invention is a porous polyurethane and polyurethane / polyisocyanurate foam made using such aromatic polyester polyols.

  The aromatic polyester polyols of the present invention can be easily blended with prior art polyols, if desired, and also various additives conventionally used in resin prepolymer blend formulations.

  Polyol blends are particularly useful in polyol formulations for making rigid foams for appliances. Such a blend comprises 10-40% by weight of the above-mentioned aromatic polyester polyol, with the balance being at least one second polyol, the second polyol having a functionality of 2-8 and a molecular weight. Is a polyether polyol, a polyester polyol or a combination thereof in which is from 100 to 2,000.

  Another aspect of the present invention provides a polyol blend for producing insulating foam for building applications, particularly building panels. Such blends will generally comprise 10-90% by weight of the aromatic polyester polyol described above, with the balance being at least one second polyol, which has a functionality of 2 A polyether polyol, a polyester polyol or a combination thereof having a molecular weight of ˜8 and a molecular weight of 100 to 10,000.

In a further aspect, the invention provides:
1) A) an aromatic component containing 80 mol% or more of terephthalic acid;
B) a polyether polyol having a nominal functionality greater than 2 and less than or equal to 4, a molecular weight of 250 to 1000, and a polyoxypropylene content of at least 70% by weight of the polyol;
C) A reaction product with a glycol or glycol mixture having a molecular weight of 60-250, wherein A, B and C are 20-60 wt.% A), 15-70 wt. A polyol component comprising 10 to 90% by weight of polyol, wherein% B) and 10 to 50% by weight C) are present;
2) polyisocyanate;
3) To provide a reaction system for producing rigid foams comprising a polyol composition optionally comprising additives and adjuvants known per se. Such optional additives or adjuvants include dyes, pigments, internal mold release agents, physical blowing agents, chemical blowing agents, flame retardants, fillers, reinforcing agents, plasticizers, anti-smoke agents, fragrances , Selected from the group consisting of antistatic agents, biocides, antioxidants, light stabilizers, adhesion promoters and combinations thereof.

  In a further aspect, the polyester polyols of the present invention comprise 10-75% by weight polyol blend in a reaction system for producing rigid foams.

In another aspect, the invention provides:
a) at least 1) the polyester of claim 1 or a mixture of said polyester and at least one other polyol, but comprising at least 10% by weight of polyester;
2) polyisocyanate;
3) forming a reactive mixture comprising at least one of a hydrocarbon, hydrofluorocarbon, hydrochlorofluorocarbon, fluorocarbon, dialkyl ether, or fluorine-substituted dialkyl ether physical blowing agent;
b) exposing the reactive mixture to conditions such that the reactive mixture expands and cures to form a rigid polyurethane foam.

  The aromatic polyester polyol of the present invention comprises at least A) terephthalic acid, B) at least one polyether polyol having a functionality greater than 2 and less than or equal to 4 and a polyoxypropylene content of at least 70% by weight of the polyol; C) prepared from a reaction mixture comprising at least one glycol component other than B) having a molecular weight of 60 to 250. It has been found that the polyesters of the present invention can be used to produce polyurethane foams with good uncured strength. Such polyesters have also been found to have good compatibility with other polyether polyols and hydrocarbon blowing agents. The term “uncured strength” refers to the basic integrity and strength of the foam upon demolding, also referred to as expansion upon demolding.

  The aromatic component (component A) of the polyester polyol of the present invention is mainly derived from terephthalic acid. The terephthalic acid component generally occupies 80 mol% or more of the aromatic content. In a further embodiment, terephthalic acid comprises 85 mol% or more of the aromatic component. In another embodiment, terephthalic acid comprises 90 mol% or more of the aromatic component for making the aromatic polyester polyol. In another embodiment, the aromatic content comprises greater than 95 mol% terephthalic acid. In another embodiment, the aromatic content is essentially derived from terephthalic acid. Polyester polyols can be prepared from substantially pure terephthalic acid, but more complex components such as sidestreams, waste or scrap residues from the production of terephthalic acid can also be used. Recycled materials that can be decomposed into terephthalic acid and diethylene glycol, such as a decomposition product of polyethylene terephthalate, can also be used.

  Component A) generally comprises 20-60% by weight of the reaction mixture. In a further embodiment, component A) represents more than 25% by weight of the reaction mixture. In a further embodiment, component A) represents no more than 55% by weight of the reaction mixture.

Polyether polyols include ethylene oxide, propylene oxide, 1,2- or 2,3-butylene oxide, tetramethylene oxide or a suitable starting molecules (initiators according to the C ₂ -C ₄ alkylene oxides, such as combinations of two or more thereof ) Obtained by alkoxylation of The polyether polyol generally comprises more than 70% by weight oxyalkylene units derived from propylene oxide (PO) units, preferably at least 75% by weight oxyalkylene units derived from PO. In other embodiments, the polyol will comprise more than 80 wt% oxyalkylene units derived from PO, and in further embodiments, 85 wt% or more oxyalkylene units are derived from PO. In some embodiments, propylene oxide will be the only alkylene oxide used in the production of polyol. When an alkylene oxide other than PO is used, it is preferable to supply an additional alkylene oxide such as ethylene oxide or butylene oxide as a joint raw material with PO or as an internal block. The catalytic reaction for such polymerization of alkylene oxides may be anionic or cationic, such as potassium hydroxide, cesium hydroxide, boron trifluoride, or the like, or zinc hexacyanocobaltate or quaternary phosphazenium. Double cyanide complex (DMC) catalysts such as compounds are used. In the case of alkaline catalysts, such alkaline catalysts are preferably removed from the polyol at the end of production by a suitable finishing step such as coalescence, magnesium silicate separation or acid neutralization.

  The polypropylene oxide polyol generally has a molecular weight of 250 to 1,000. In one embodiment, the molecular weight is 260 or greater. In further embodiments, the molecular weight will be less than 800, or even less than 600. In a further embodiment, the molecular weight is less than 500.

  The initiator to produce component B has a functionality greater than 2 and less than or equal to 4; that is, greater than 2 and up to 4 active hydrogens. As used herein, unless otherwise indicated, functionality refers to nominal functionality. For example, non-limiting examples of such initiators include amino alcohols such as glycerol, trimethylolpropane, ethylenediamine and ethanolamine. In a further embodiment, the initiator for the polyether contains 3 active hydrogen atoms.

  The propylene oxide-based polyol generally accounts for 10 to 70% by weight of the reaction mixture. In a further embodiment, the propylene oxide-based polyol represents 10-60% by weight of the reaction mixture. In another embodiment, the polypropylene oxide based polyol comprises less than 50% by weight of the reaction mixture.

  In addition to the aromatic component A) and the polypropylene oxide-based polyol component B), the reaction mixture for producing the polyester polyol differs from component B) in that one or more glycols (components) having a molecular weight of 60 to 250 C)). Such glycols or glycol blends generally have a nominal functionality of 2-3. Component C) may contain glycols with a functionality greater than 3 to prevent an increase in the viscosity of the material, but it is generally preferred that the functionality of such glycol blends containing component C) be 3 or less.

  In one embodiment, the difunctional glycol of component C) has the formula

で表すことができ、式中、Ｒは水素、または炭素原子１〜４個の低級アルキルであり、ｎは分子量２５０以下になるように選択される。さらなる実施形態では、ｎは、分子量２００未満になるように選択される。さらなる実施形態では、Ｒは水素である。本発明で使用できるジグリコールの非限定的な例として、エチレングリコール、ジエチレングリコール、および他のポリエチレングリコール、プロピレングリコール、ジプロピレングリコールなどが挙げられる。例えば、三官能価グリコールとしてグリセリンおよびトリメチロールプロパンが挙げられる。一実施形態では、グリコール成分Ｃ）は、２つ以上のグリコールの組合せを含む。かかる組合せの例として、グリセロールとジエチレングリコール；ジエチレングリコールと分子量が１５０超であるポリエチレングリコールが挙げられる。

Wherein R is hydrogen or lower alkyl of 1 to 4 carbon atoms and n is selected to have a molecular weight of 250 or less. In a further embodiment, n is selected to be less than 200 molecular weight. In a further embodiment, R is hydrogen. Non-limiting examples of diglycols that can be used in the present invention include ethylene glycol, diethylene glycol, and other polyethylene glycols, propylene glycol, dipropylene glycol, and the like. For example, trifunctional glycols include glycerin and trimethylolpropane. In one embodiment, glycol component C) comprises a combination of two or more glycols. Examples of such combinations include glycerol and diethylene glycol; diethylene glycol and polyethylene glycol having a molecular weight greater than 150.

  Component C) generally represents more than 10% by weight of the reaction mixture for producing the polyester and generally less than 50% by weight of the reaction mixture for producing the polyester. In another embodiment, the glycol component comprises more than 15% by weight of the reaction mixture. In a further embodiment, the glycol component is less than 45% by weight of the reaction mixture.

  It is believed that the inclusion of components A), B) and C) in the one-shot synthesis allows the aromatic component, polyether polyol and glycol to react randomly. Based on the components in producing the polyester, the polyester will have a nominal functionality between 2.4 and 3.0, generally between 2.5 and 2.9. The amount of material used in making the polyester generally results in a polyester having a hydroxyl number of 200-400. In a further embodiment, the polyester has a hydroxyl number of less than 350.

  By including the specified amount of polypropylene oxide-based polyol along with other glycols as described above, along with the aromatic component, the viscosity of the resulting polyester is generally 60, 25 ° C. as measured by UNI EN ISO 3219. Less than 000 mPa * s. In a further embodiment, the viscosity of the polyester polyol is less than 50,000 mPa * s. Although it is desirable to include polyols with as low a viscosity as possible, due to practical chemical constraints and end uses, the viscosity of the polyol will generally exceed 2,000 mPa * s.

  The aromatic polyester polyol of the present invention may contain any small amount of unreacted glycol remaining after preparation of the polyester polyol. Although not desirable, the aromatic polyester polyol can comprise up to about 30% by weight free glycol / polyol. The free glycol content of the aromatic polyester polyols of the present invention is generally about 0 to about 30% by weight, usually 1 to about 25% by weight, based on the total weight of the polyester polyol component. Polyester polyols can also contain small amounts of residual non-esterified aromatic components. Usually, the non-esterified aromatic material is present in an amount of less than 2% by weight, based on the total weight of the components combined to form the aromatic polyester polyol of the present invention.

  Polyester polyols can be formed by polycondensation / transesterification and polymerization of components A, B, and C under conditions well known in the art. See, for example, G. Oertel, Polyurethane Handbook, Carl Hanser Verlag, Munich, Germany, 1985, 54-62 and Mihail Ionescu, Chemistry and Technology of Polyols for Polyurethanes, Rapra Technology, 2005, 263-294. . In general, the synthesis is carried out at a temperature of 180-280 ° C. In another embodiment, the synthesis is performed at a temperature of at least 200 ° C. In a further embodiment, the synthesis is performed at a temperature of 215 ° C or higher. In a further embodiment, the synthesis is performed at a temperature of 260 ° C. or lower.

  The synthesis may be carried out under reduced pressure or elevated pressure, but the reaction is generally carried out under conditions near atmospheric pressure.

  The synthesis may be carried out without a catalyst, but catalysts that promote esterification / transesterification / polymerization reactions can also be used. Examples of such catalysts include tetrabutyl titanate, dibutyltin oxide, potassium methoxide, or oxides of zinc, lead or antimony; titanium compounds such as titanium (IV) isopropoxide and titanium acetylacetonate. When used, such catalysts are used in amounts of 0.005 to 1% by weight of the total mixture. In a further embodiment, the catalyst is present in an amount from 0.005 to 0.5% by weight of the total mixture.

  The volatile product (s) of the reaction, such as water and / or methanol, are generally removed overheaad in the process to complete the transesterification reaction.

  The synthesis usually takes 1 to 5 hours. Of course, the required real time will vary with catalyst concentration, temperature, etc. In general, it is desirable not to lengthen the polymerization cycle too much for economic reasons and because thermal degradation can occur if the polymerization cycle is too long.

  The polyesters of the present invention can also be used as part of a polyol formulation to produce a variety of polyurethane or polyisocyanurate products. Polyols, also called isocyanate-reactive components, together with the isocyanate components provide us with a system for producing polyurethanes or polyisocyanurates. Polyesters can be used as part of a formulation for producing polyurethanes and can be particularly adapted in formulations for producing rigid foams.

  The polyesters of the present invention can be used alone or can be blended with other known polyols to produce polyol blends. Depending on the application, the polyester is generally in the range of 10-90% by weight of the total polyol formulation. The amount of polyester polyol that can be used for a particular application can be readily determined by one skilled in the art. For example, for formulations in rigid foam building applications, the polyester can generally account for 10 to up to 80% by weight of the polyol formulation. In other such embodiments, the polyester comprises less than 70% by weight of the polyol formulation. In appliance insulation formulations for rigid foam applications, the polyester will generally be 40% or less by weight of the polyol blend.

  Exemplary polyols include polyether polyols, polyester polyols different from the polyesters of the present invention, polyhydroxy-terminated acetal resins, and hydroxyl-terminated amines. Alternative polyols that can be used include polyalkylene carbonate-based polyols and polyphosphate-based polyols. Polyether or polyester polyols are preferred. Polyether polyols are prepared by adding alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide or combinations thereof to an initiator having 2 to 8 active hydrogen atoms. The functionality of the polyol (s) used in the formulation will depend on the end use known to those skilled in the art. Such polyols advantageously have a functionality of at least 2, preferably 3, at most 8, preferably at most 6, active hydrogen atoms per molecule. Polyols used for rigid foams generally have a hydroxyl number of about 200 to about 1,200, more preferably about 250 to about 800. For certain applications, monols can also be used as part of the polyol formulation.

  Polyols derived from renewable resources such as vegetable oils and animal fats can also be used as additional polyols. Examples of such polyols include castor oil, hydroxymethylated polyesters described in WO 04/096882 and WO 04/096883, US Pat. Nos. 4,423,162, 4,496,487 and 4,543,369. And the “foamed” vegetable oils described in US 2002/0121328, 2002/0119321 and 2002/0090488.

  Generally for reacting with isocyanates for the purpose of improving reactivity for polyol systems, reducing demold time, reducing thermal conductivity and / or imparting dimensional stability to the final rigid foam. In addition to the polyester polyol of the present invention, the polyol component generally comprises from 5 to 60% by weight of a polyol obtained from an initiator containing at least one amine group. Such amine-initiated polyols generally have a functionality of 2-8, preferably 3-8, and an average hydroxyl number of about 200 to about 850, preferably about 300 to about 770. In further embodiments, the amine-initiated polyol comprises at least 10, at least 15, at least 20 or at least 25 parts by weight of the polyol formulation. Amine-initiated polyols may have catalytic activity primarily with respect to foam cure due to the presence of nitrogen atoms and may affect the foaming reaction.

  In further embodiments, the initiator for the amine-initiated polyol is an aromatic amine, an aliphatic amine or an alicyclic amine. Examples of alicyclic amines include methylene bis (cyclohexylamine; 1,2-, 1,3- or 1,4-bis (aminomethyl) cyclohexane; aminocyclohexanealkylamine; 2- or 4-alkylcyclohexane-1,3. Examples of linear alkylamines include, for example, ethylenediethanolamine, N-methyldiethanolamine, ethylenediamine, diethanolamine, diisopropanolamine, monoisopropanolamine and the like. Examples of suitable aromatic amine initiators include, for example, piperazine, aminoethylpiperazine, 1,2-, 1,3- and 1,4-phenylenediamine; 2,3-, 2,4-, 3 4- and 2,6-toluenediamines; 4,4'-, 2,4'- and 2,2'-diaminodiphenylmethanes; polyphenyl-polymethylene-polyamines, in one embodiment, with the polyesters of the present invention. The polyol component used is a toluene diamine (TDA) initiated polyol, more preferably at least 85% by weight of TDA is ortho-TDA.Ethylene diamine- and toluene diamine-initiated polyols are used with the polyesters of the present invention. Is a preferred amine-initiated polyol.

  In addition to the amine-initiated polyol, in order to increase the cross-linking network, the polyol blend can include higher functionality polyols with a functionality of 5-8. Examples of initiators for such polyols include pentaerythritol, sorbitol, sucrose, glucose, fructose or other sucrose. With respect to amine-initiated polyols, such higher functionality polyols have an average hydroxyl number of from about 200 to about 850, preferably from about 300 to about 770. Other initiators, such as glycerin, can be added to higher functionality polyols to give the co-initiated polyol a functionality of 4.5-7 hydroxyl groups per molecule and a hydroxyl equivalent weight of 100-175. Can do. When used, such polyols generally comprise 5-60% by weight of the polyol formulation for making rigid foams, depending on the particular application.

  The polyol mixture may contain up to 20% by weight of another additional polyol, which is not a polyester, an amine-initiated polyol or a higher functionality polyol and has a hydroxyl functionality of 2.0-3. 0.0 and the hydroxyl equivalent weight is 90-600. For architectural applications, the polyol blend can also include a polyol that is an alkoxylation product of a phenol-formaldehyde resin. Such polyols are known in the art as novolak polyols. When used in formulations, such novolak polyols can be present in amounts up to 40% by weight.

  In one embodiment, the present invention provides a polyol blend comprising 10-90% by weight of the above-described aromatic polyester polyol, with the remainder having a functionality of 2-8 and a molecular weight of 100-10,000. At least one polyol or combination of polyols.

  As a specific example of a polyol mixture suitable for producing a rigid foam for electrical appliance insulation, 10 to 50% by weight of the polyester of the present invention, 10 to 60% by weight and a functionality of 3 to 8 At least one amine-initiated polyol having an average hydroxyl number of from about 200 to about 850, and 10 to 45% by weight of a sorbitol or sucrose / glycerin-initiated polyether polyol, wherein the polyol or polyol blend has a functionality of 5 A mixture of a polyether polyol of ˜8 and a hydroxyl equivalent weight of 200 to 850 with up to 20% by weight of another polyol having a hydroxyl functionality of 2.0 to 3.0 and a hydroxyl equivalent weight of 30 to 500 Is mentioned.

  The polyol mixture described can be prepared by preparing the component polyols individually and then blending them together. Alternatively, a polyol-free polyol mixture can also be prepared by forming a mixture of individual initiator compounds and then alkoxylating the initiator mixture to form the polyol mixture directly. Combinations of these techniques can also be used.

  For rigid foam applications, the polyols used with polyester polyols are generally based on polyoxypropylene, i.e., contain 70% or more by weight of polyoxypropylene units.

  Suitable polyisocyanates for producing the polyurethane product include aromatic, alicyclic and aliphatic isocyanates. Such isocyanates are well known in the art. Examples of suitable aromatic isocyanates include 4,4'-, 2,4 'and 2,2'-isomers of diphenylmethane diisocyanate (MDI), blends and polymers and monomeric MDI blends, toluene-2,4- And 2,6-diisocyanate (TDI), m- and p-phenylene diisocyanate, chlorophenylene-2,4-diisocyanate, diphenylene-4,4′-diisocyanate, 4,4′-diisocyanate-3,3′-dimethyldiphenyl 3-methyldiphenyl-methane-4,4′-diisocyanate and diphenyl ether diisocyanate, and 2,4,6-triisocyanatotoluene and 2,4,4′-triisocyanatodiphenyl ether.

  Crude polyisocyanates such as crude toluene diisocyanate obtained by phosgenation of a toluenediamine mixture and crude diphenylmethane diisocyanate obtained by phosgenation of crude methylenediphenylamine can also be used in the practice of the present invention. In one embodiment, a TDI / MDI blend is used.

Examples of aliphatic polyisocyanates include ethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,3- and / or 1,4-bis (isocyanatomethyl) cyclohexane (either cis- or trans-isomers) ), Isophorone diisocyanate (IPDI), tetramethylene-1,4-diisocyanate, methylene bis (cyclohexane isocyanate) (H ₁₂ MDI), cyclohexane 1,4-diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, the above aromatic isocyanate And saturated analogs thereof, and mixtures thereof.

  Derivatives of any of the aforementioned polyisocyanate groups, including biuret, urea, carbodiimide, allophonate and / or isocyanurate groups can also be used. Such derivatives often have increased isocyanate functionality and are preferably used when products with a higher degree of crosslinking are desired.

  When producing rigid polyurethane or polyisocyanurate materials, the polyisocyanate is generally diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, polymers or derivatives thereof, or mixtures thereof. In a preferred embodiment, the isocyanate-terminated prepolymer is prepared using 4,4′-MDI or other MDI blends containing a substantial portion of the 4,4′-isomer or MDI modified as described above. . Preferably, the MDI contains 45 to 95% by weight of the 4,4'-isomer.

  The isocyanate component may be in the form of an isocyanate-terminated prepolymer formed by reacting excess isocyanate with a polyol or polyester, including the polyester of the present invention.

  The polyesters of the present invention can be used to produce hydroxyl-terminated prepolymers formed by reacting excess polyester with isocyanates.

  The polyisocyanate is used in an amount sufficient to provide an isocyanate index of 80-600. The isocyanate index is calculated by dividing the number of reactive isocyanate groups provided by the polyisocyanate component by the number of isocyanate reactive groups in the polyurethane-forming composition (including those contained by isocyanate-reactive blowing agents such as water). Calculated by multiplication. Water is considered to have two isocyanate-reactive groups per molecule for purposes of calculating the isocyanate index. A preferred isocyanate index is 90-400. For rigid foam applications, the isocyanate index is generally 100-150. For polyurethane-polyisocyanurate products, the isocyanate index is generally greater than 150 and up to 800.

  It is also possible to use one or more chain extenders in the formulation to produce the polyurethane product. The presence of a chain extender provides the desired physical properties of the resulting polymer. The chain extender may be blended with the polyol component and may be present as a separate stream during the formation of the polyurethane polymer. A chain extender is a material having two isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of less than 400, preferably less than 300, in particular 31 to 125 daltons. Crosslinking agents can also be included in the formulation for producing the polyurethane polymers of the present invention. “Crosslinking agent” is a material having 3 or more isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of less than 400. The cross-linking agent preferably contains 3 to 8, in particular 3 to 4, hydroxyl, primary amine groups or secondary amine groups per molecule and has an equivalent weight of 30 to about 200, in particular 50 to 125.

  The polyester polyols of the present invention can be used with a variety of blowing agents. The blowing agent used in the polyurethane-forming composition comprises at least one physical blowing agent, which is a hydrocarbon, hydrofluorocarbon, hydrochlorofluorocarbon, fluorocarbon, dialkyl ether or fluorine-substituted dialkyl ether, Or a mixture of two or more thereof. These types of blowing agents include propane, isopentane, n-pentane, n-butane, isobutane, isobutene, cyclopentane, dimethyl ether, 1,1-dichloro-1-fluoroethane (HCFC-141b), chlorodifluoromethane (HCFC- 22), 1-chloro-1,1-difluoroethane (HCFC-142b), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1,3,3-pentafluorobutane (HFC) -365mfc), 1,1-difluoroethane (HFC-152a), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) and 1,1,1,3,3-pentafluoro Propane (HFC-245fa) is mentioned. Hydrocarbon and hydrofluorocarbon blowing agents are preferred. The polyesters of the present invention show good compatibility with hydrocarbon blowing agents such as various isomers of pentane and butane. In a further embodiment, the hydrocarbon blowing agent used is cyclopentane. It is generally preferred to further include water in the formulation in addition to the physical blowing agent.

The blowing agent (s) are preferably cured to form a foam having a molding density of 16 to 160 kg / m ³ , preferably 16 to 64 kg / m ³ , especially 20 to 48 kg / m ^3. Used in an amount sufficient to do. To achieve such density, the hydrocarbon or hydrofluorocarbon blowing agent is conveniently in the range of about 10 to about 40, preferably about 12 to about 35 parts by weight per 100 parts by weight of polyol (s). Used in quantity. Water reacts with isocyanate groups to produce carbon dioxide, which acts as an expanding gas. Water is suitably used in an amount in the range of 0.5 to 3.5, preferably 1.0 to 3.0 parts by weight per 100 parts by weight of polyol (s).

  The polyurethane-forming composition typically comprises at least one catalyst for reacting the polyol (s) and / or water with the polyisocyanate. Suitable urethane forming catalysts include those described in US Pat. No. 4,390,645 and WO 02/079340, both of which are incorporated herein by reference. Typical catalysts include tertiary amine and phosphine compounds, various metal chelates, strong acid acidic metal salts, strong bases, various metal alcoholates and phenolates, various metal salts of organic acids, tetravalent tin, Trivalent and pentavalent organometallic derivatives of As, Sb and Bi, and metal carbonyls of iron and cobalt.

  Tertiary amine catalysts are generally preferred. Among the tertiary amine catalysts are dimethylbenzylamine (such as Desmorapid® DB from Rhine Chemie), 1,8-diaza (5,4,0) undecane-7 (Polycat from Air Products). (Registered trademark) SA-1), pentamethyldiethylenetriamine (such as Polycat® 5 from Air Products), dimethylcyclohexylamine (such as Polycat® 8 from Air Products), triethylenediamine (Air) N-alkyldimethylamination such as Dabco (registered trademark) 33LV manufactured by Products), dimethylethylamine, n-ethylmorpholine, N-ethyl N, N-dimethylamine and N-cetyl N, N-dimethylamine And N-alkylmorpholine compounds such as N-ethylmorpholine and N-cocomorpholine. Other tertiary amine catalysts that are useful include the trade names Dabco® NE1060, Dabco® NE1070, Dabco® NE500, Dabco® TMR-2, Dabco® TMR30. , Polycat (R) 1058, Polycat (R) 11, Polycat 15, Polycat (R) 33, Polycat (R) 41 and Dabco (R) MD45 sold by Air Products, and merchandise Those sold by Huntsman under the names ZR50 and ZR70. In addition, certain amine-initiated polyols, including those described in WO 01 / 58976A, can also be used in the present invention as catalyst materials. Mixtures of two or more of the foregoing can also be used.

  The catalyst is used in a sufficient amount as a catalyst. In the preferred tertiary amine catalyst, the appropriate amount of catalyst is from about 1 to about 4, in particular from about 1.5 to about 3 parts of tertiary amine catalyst (s) per 100 parts by weight of polyol (s). It is.

  The polyurethane-forming composition also preferably includes at least one surfactant that stabilizes the vesicles of the composition as the gas evolves to form bubbles and expand the foam. To help. Examples of suitable surfactants include alkali metal and amine salts of fatty acids such as sodium oleate, sodium stearate, sodium ricinoleate, diethanolamine oleate, diethanolamine stearate, diethanolamine ricinoleate; dodecylbenzenesulfonic acid and dinaphthyl Alkali metal and amine salts of sulfonic acids such as methanedisulfonic acid; ricinoleic acid; siloxane-oxalalkylene polymers or copolymers and other organopolysiloxanes; oxyethylated alkylphenols (such as Tergitol NP9 and Triton X100 from The Dow Chemical Company) ); Such as Tergitol 15-S-9 made by The Dow Chemical Company Xyethylated fatty alcohol; paraffin oil; castor oil; ricinoleic acid ester; Turkish red oil; peanut oil; paraffin; aliphatic alcohol; dimethylpolysiloxane and oligomeric acrylate containing polyoxyalkylene and fluoroalkane side groups . Such a surfactant is generally used in an amount of 0.01 to 6 parts by weight based on 100 parts by weight of polyol.

  Organosilicone surfactants are generally the preferred type. Those sold by Goldschmidt under the Tegostab® name (such as Tegostab B-8462, B8427, B8433, and B-8404 surfactants) and those sold by OSi Specialties under the Niax® name Commercially available from Air Products and Chemicals (such as Niax® L6900 and L6988 surfactants), and DC-193, DC-198, DC-5000, DC-5043 and DC-5098 surfactants. A variety of such organosilicone surfactants are commercially available, including a variety of surfactant products.

  In addition to the aforementioned components, the polyurethane-forming composition has a variety of auxiliary agents such as fillers, colorants, odor control agents, flame retardants, biocides, antioxidants, UV stabilizers, antistatic agents, viscosity modifiers and the like. Ingredients can be included.

  Examples of suitable flame retardants include phosphorus compounds, halogen-containing compounds and melamine.

  Examples of fillers and pigments include calcium carbonate, titanium dioxide, iron oxide, chromium oxide, azo / diazo dyes, phthalocyanines, dioxazines, recycled rigid polyurethane foams and carbon black.

  Examples of UV stabilizers include hydroxybenzotriazole, zinc dibutylthiocarbamate, 2,6-di-tert-butylcatechol, hydroxybenzophenone, hindered amine and phosphite.

  Except for fillers, the aforementioned additives are generally used in small amounts. Each can account for 0.01% to 3% of the total weight of the polyurethane formulation. Fillers can be used in amounts as high as 50% of the total weight of the polyurethane formulation.

  Polyurethane-forming compositions are made by combining various components under conditions where the polyol (s) and isocyanate (s) react, the blowing agent generates gas, and the composition expands and cures. Prepared. All components except the polyisocyanate (or any subcombination thereof) can be pre-blended into a blended polyol composition, if desired, and then this blended polyol composition in the foam preparation stage. The product is mixed with the polyisocyanate. The components can be preheated if desired, but this preheating is usually not necessary and the components can be allowed to run together at about room temperature (about 22 ° C.). It is not usually necessary to accelerate the cure by applying heat to the composition, but it can also be performed if desired.

  The present invention is particularly useful in so-called “in-situ injection” applications, where the polyurethane-forming composition is dispensed into a cavity and foams into the cavity to fill the cavity, Provide structural and / or thermal insulation properties to the assembly. The name “in-situ injection” refers to the fact that the foam is created at the required location, rather than being created at one stage and then incorporated into the required location at a separate manufacturing stage. In-situ injection processes are typically used to make appliance products such as refrigerators, freezers and coolers and similar products with walls that contain insulating foam. The presence of an amine-initiated polyol in addition to the high functionality polyester polyol in the polyurethane-forming composition tends to result in a formulation with good flowability and short demolding time, but at the same time results in a foam with a low k-factor. It is.

  The walls of appliances such as refrigerators, freezers and coolers are most conveniently insulated according to the present invention by first assembling the outer shell and inner liner such that a cavity is formed between the outer shell and the liner. The This cavity defines the space to be insulated, as well as the size and shape of the foam to be produced. Typically, the shell and liner are joined by some method, such as by welding, melt bonding or the use of some adhesive (or some combination thereof) prior to introducing the foam formulation. In most cases, the shell and liner can be supported or held in the correct relative position using a jig or other instrument. One or more inlets to the cavity are provided, from which the foam formulation can be introduced. Typically, one or more outlets are provided so that the air in the cavity can escape as the cavity is filled with the foam composition and the foam composition expands.

  The structural material for the shell and liner is not particularly critical if it can withstand the conditions of the curing and expansion reactions of the foam formulation. In most cases, the structural material is selected for the specific performance characteristics desired in the final product. Metals such as steel are usually used as the outer shell, but this is especially true for relatively large appliances such as freezers and refrigerators. Plastics such as polycarbonate, polypropylene, polyethylene, styrene-acrylonitrile resin, acrylonitrile-butadiene-styrene resin or high impact polystyrene are more often used in relatively small appliances (such as coolers) or appliances where lightweight is important. used. The liner may be metal, but plastic is more common, just as described.

  A foam formulation is then introduced into the cavity. The various components of the foam formulation are mixed together and the mixture is quickly introduced into the cavity and the components react and expand. It is common to premix polyol (s) with water and blowing agents (and often also catalysts and / or surfactants) to form formulated polyols. The compounded polyol can be stored until the foam is prepared, mixed with the polyisocyanate at the time of preparation, and introduced into the cavity. Normally, it is not necessary to heat the component before introducing the component into the cavity, and it is usually not necessary to heat the formulation within the cavity to promote curing. However, if desired, one or both of these steps can be performed. The shell and liner may in some cases serve as a heat sink and remove heat from the reacting foam formulation. If necessary, the shell and / or liner may be somewhat heated (such as up to 50 ° C. and more usually up to 35-40 ° C.) to reduce this heat sink effect and to promote curing. Good.

After the foam formulation has expanded, sufficient foam formulation is introduced so that the resulting foam fills the portion of the cavity where the foam is desired. Most commonly, essentially the entire cavity is filled with foam. It is generally preferred to slightly “overfill” the cavity by introducing a foam formulation in excess of the minimum required to fill the cavity and slightly increasing the foam density. Overfilling provides advantages such as better dimensional stability of the foam, especially in the period after demolding. Generally, the cavity is overfilled by 4-20% by weight. When using vacuum assisted injection, the overfill may be up to 40% by weight. The final foam density for most appliance applications is preferably in the range of 28-40 kg / m ³ .

  After the foam formulation swells and cures until sufficient dimensional stability is obtained, the production assembly is removed from the jig or other support used to hold the outer shell and liner in the correct relative position. It can be “demolded” by removing it. Short demolding time is important for the appliance industry. The reason is that the shorter the demolding time, the larger the amount of members created per unit time with a given manufacturing apparatus. The assembly line can also include either a movable or stationary jig. The polyester polyols of the present invention are particularly suitable when a demolding time of less than 10 minutes is desired. Polyester polyols can also be used to achieve demold times of less than 7 minutes, or even less than 6 minutes.

  If desired, the step of generating the appliance can also be performed in conjunction with the vacuum assisted injection (VAI) method described, for example, in WO 2007/058793 and WO 2010/044361. In this method, the reaction mixture is injected into a closed mold cavity that is under reduced pressure. In the VAI method, the mold pressure is 300-950 mbar (30-95 kPa), preferably 400-900 mbar (40-90 kPa), even more preferably, immediately before or after the foam-forming composition is charged into the mold. Is reduced to 500-850 mbar (50-85 kPa). Furthermore, the filling factor (ratio of the density of the molded foam divided by its free rise density) should be 1.03 to 1.9.

  The following examples are provided to illustrate the invention and are not intended to limit its scope. All parts and percentages are by weight unless otherwise indicated.

The description of the raw materials used in the examples is as follows.
VORANOL CP 450 is a glycerin-initiated polyoxypropylene polyol having a molecular weight of about 450.
VORANOL CP 260 is a glycerin-initiated polyoxypropylene polyol having a molecular weight of about 260.
VORANOL ™ RN482 polyol is a sorbitol-initiated polyoxypropylene polyol having a molecular weight of about 700. VORANOL is a trademark of The Dow Chemical Company.
Polyol 1 is a glycerin-initiated polyoxypropylene polyol having a molecular weight of about 1050.
Polyol 2 is an orthotoluenediamine initiated polyoxypropylene polyol having a molecular weight of about 510.
VORANOL 640 polyol is an ethylenediamine-initiated polyoxypropylene polyol having a molecular weight of about 350.
DABCO TMR-30 is a delayed action gelling catalyst commercially available from Air Products. (DABCO is a trademark of Air Products Corporation.)
NIAX L-6900 is a silicone surfactant commercially available from Momentive. (NIAX is a trademark of Momentive Performance Materials Inc.)
POLYCAT 5 is a foaming catalyst that is commercially available from Air Products. (POLYCAT is a trademark of Air Products Corporation.)
Stepanpol PS 3152 is a diethylene glycol-phthalic anhydride-based polyester polyol having a hydroxyl value of 290-325 and a functionality of 2, available from Stepan Company.
Stepanpol PS 2352 is a phthalic anhydride-based polyester polyol with a hydroxyl value of 235, available from Stepan Company.
The reference polyester is a terephthalic acid-based polyester polyol having a hydroxyl value of 315 and a viscosity at 25 ° C. of 600 cP.
Polyester # 1 is a terephthalic acid-based polyester polyol having a hydroxyl value of 235, a viscosity at 25 ° C. of 6,000 cP, and a functionality of 3.0.
Polyester # 2 is a terephthalic acid polyester polyol having a hydroxyl value of 235, a viscosity at 25 ° C. of 14,000 cP, and a functionality of 2.9.
Polyester # 3 is a terephthalic acid-based polyester polyol having a hydroxyl value of 315, a viscosity at 25 ° C. of 14,000 cP, and a functionality of 2.9.
PAPI 27 isocyanate is a polymethyl polyphenyl isocyanate containing MDI having an average functionality of 2.7 and a molecular weight of 340.

  Generation of reference polyester. Raw materials, ie, 2000 grams of diethylene glycol (25.8 wt%), polyethylene glycol 200 (42.2 wt%), and terephthalic acid (32 wt%) were added to the nitrogen inlet tube, air stirrer, thermometer and condenser. Charge to a 3000 ml glass flask equipped. Heat and raise flask contents to 230-235 ° C. At a temperature of 180 ° C., a titanium acetylacetonate catalyst (Tyzor AA-105 manufactured by Du Pont) is charged (50 ppm), and a flow of nitrogen is slightly applied. The mixture is held at 230-235 ° C. for 8 hours. The polyester polyol at this point has an acid number of less than 2 mg KOH / g. Cool the flask contents to room temperature under atmospheric pressure conditions.

  Formation of polyester # 1. The raw materials, ie, 2000 grams of diethylene glycol (15.3% by weight), VORANOL CP450 polyol (59.7% by weight) and terephthalic acid (25% by weight) are charged to the apparatus described in the reference polyester. The method for producing the polyester is similar to that shown for producing the reference polyester.

  Formation of polyester # 2. A device in which 2000 grams of raw materials, namely diethylene glycol (12 wt%), VORANOL CP260 polyol (29.8 wt%), polyethylene glycol PEG200 (23.2 wt%) and terephthalic acid (35 wt%) were described in reference polyester. To charge. The method for producing the polyester is similar to that shown for producing the reference polyester.

  Formation of polyester # 3. The raw materials, ie, 2000 grams of diethylene glycol (24.8% by weight), VORANOL CP450 polyol (40.2% by weight) and terephthalic acid (35% by weight) are charged to the apparatus described in the reference polyester. The method for producing the polyester is similar to that shown for producing the reference polyester.

Examples 1-3
Polyurethane foam for refrigerated cabinets was prepared using the polyester polyol described above. The polyol formulation is shown in Table 1.

  The properties of the reference formulation and the properties of polyesters 1-3 are shown in the table along with the stability of the polyol formulation.

  Polyester polyols # 1, # 2 and # 3 are liquid at room temperature, have a manageable viscosity, and have a long shelf life (stability). When used in a polyol blend, it also resulted in a stable polyol formulation as shown in Table 2.

  Foam is produced using a high pressure machine Hi-Tech Eco-RIM. Preheat both the polyol formulation and PAPI27 to 70 ± 2 F before mixing with the high pressure impact mixer. Dispense the reaction mixture into an aluminum mold (Brett mold 200 × 20 × 5 cm) preheated to 125F. Demold expansion is measured with 10% overfill by opening the mold 3 minutes after injection. The maximum expansion of the mold lid is then recorded. Samples for k-factor and compressive strength are post-cured overnight before cutting. Once cut, the foam samples were tested within 4 hours. Compressive strength was measured according to ASTM D1621, and k-factor was measured according to ASTM C518. Table 3 shows the results obtained by the machine test.

  As shown in Table 3, all TPA-based polyesters provide an improvement in demold expansion, but polyesters made without propoxylated glycerin have lower compressive strength and poor stability in polyol formulations Met. Grades containing propoxylated glycerin retained improvement in demold expansion compared to phthalic anhydride polyol and did not sacrifice compressive strength. Such polyesters also resulted in formulations that were fully compatible with hydrocarbon blowing agents.

  Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification or practice of the invention disclosed herein. The specification and examples should be considered as exemplary only, with the true scope and spirit of the invention being intended to be indicated by the following claims.

Claims (12)

At least A) an aromatic component containing 80 mol% or more of terephthalic acid,
B) at least one polyether polyol having a nominal functionality of greater than 2 and less than or equal to 4, a molecular weight of 250 to 1000, and a polyoxypropylene content of at least 70% by weight of the polyol;
C) comprising a reaction product with at least one glycol other than B having a molecular weight of 60-250, wherein A, B and C are in the reaction product 20-60 wt% A) Polyester polyol in which 15 to 70% by weight of B) and 10 to 50% by weight of C) are present.   The polyester polyol according to claim 1, comprising terephthalic acid having an aromatic content of 85 mol% or more.   The polyester polyol according to claim 2, comprising terephthalic acid having an aromatic content of 95 mol% or more.   The polyester polyol according to any one of claims 1 to 3, wherein the functionality of the polyol is 2.4 to 3.   5. Polyester polyol according to claim 4, wherein the polyether polyol B) has a molecular weight of less than 800.   6. Polyester polyol according to claim 5, wherein the functionality of glycol C) is 2-3. The bifunctional glycol is

(Wherein R is hydrogen or lower alkyl having 1 to 4 carbon atoms, and n is selected to have a molecular weight of 250 or less)
The polyester polyol of claim 6 represented by:   8. Polyester polyol according to claim 7, wherein glycol C) is a mixture of difunctional glycol and trifunctional glycol.   The polyester polyol according to claim 8, wherein the trifunctional glycol is glycerol, trimethylolpropane or a combination thereof. i) at least A) an aromatic component containing 80 mol% or more of terephthalic acid;
B) at least one polyether polyol having a nominal functionality of greater than 2 and less than or equal to 4, a molecular weight of 250 to 1000, and a polyoxypropylene content of at least 70% by weight of the polyol;
C) comprising a reaction product with at least one glycol other than B) having a molecular weight of 60 to 250, wherein A, B and C are 20 to 60% by weight of A) in the reaction product. 10-90% polyester polyol with 15-70% by weight B) and 10-50% by weight C) present;
ii) A polyol mixture comprising 10 to 90% by weight of a polyol or polyol blend other than i) having a functionality of 2 to 8 and a molecular weight of 100 to 10,000. At least 10 to 50% by weight of the polyester according to claim 1;
10-60% of at least one amine-initiated polyol having a functionality of 3-8 and an average hydroxyl number of about 200 to about 850;
10 to 45% by weight of a sorbitol or sucrose / glycerin initiated polyether polyol, wherein the polyol or polyol blend has a functionality of 5 to 8 and a hydroxyl equivalent weight of 200 to 850,
A polyol mixture comprising up to 20% by weight of another polyol having a hydroxyl functionality of 2.0 to 3.0 and a hydroxyl equivalent weight of 30 to 500. a) at least 1) the polyester of claim 1 or a mixture of said polyester and at least one other polyol, but comprising at least 10% by weight of polyester;
2) polyisocyanate;
3) forming a reactive mixture comprising at least one of a hydrocarbon, hydrofluorocarbon, hydrochlorofluorocarbon, fluorocarbon, dialkyl ether, or fluorine-substituted dialkyl ether physical blowing agent;
b) exposing the reactive mixture to conditions such that the reactive mixture expands and cures to form a rigid polyurethane foam.